U.S. patent number 8,051,658 [Application Number 12/727,946] was granted by the patent office on 2011-11-08 for hydraulic element.
This patent grant is currently assigned to Luk Vermoegensverwaltungsgesellschaft mbH. Invention is credited to Jan Grabenstaetter, Thomas Rammhofer.
United States Patent |
8,051,658 |
Rammhofer , et al. |
November 8, 2011 |
Hydraulic element
Abstract
A hydraulic element, in particular for arranging in a pressure
line between a master cylinder and a slave cylinder of a hydraulic
clutch actuating arrangement, having a housing which has a
master-cylinder-side hydraulic connection and a slave-cylinder-side
hydraulic connection and which holds a valve arrangement, a simpler
design is obtained in that the valve arrangement has two valve
bodies which are mounted in a floating fashion in the housing and
which can be moved relative to one another counter to the force of
a spring.
Inventors: |
Rammhofer; Thomas (Sasbach,
DE), Grabenstaetter; Jan (Gernsbach, DE) |
Assignee: |
Luk
Vermoegensverwaltungsgesellschaft mbH (Buehl,
DE)
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Family
ID: |
40079927 |
Appl.
No.: |
12/727,946 |
Filed: |
March 19, 2010 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20100242468 A1 |
Sep 30, 2010 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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PCT/DE2008/001438 |
Aug 28, 2008 |
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Foreign Application Priority Data
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Sep 20, 2007 [DE] |
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10 2007 045 034 |
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Current U.S.
Class: |
60/591 |
Current CPC
Class: |
F16D
25/12 (20130101); F16D 25/088 (20130101); F16D
25/082 (20130101); F16D 48/02 (20130101); F16D
2048/0215 (20130101); F16D 2048/0221 (20130101); F16D
2300/22 (20130101) |
Current International
Class: |
F16D
31/02 (20060101) |
Field of
Search: |
;60/591
;137/493.6,493,512.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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4417961 |
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Nov 1995 |
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DE |
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10059382 |
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Jun 2001 |
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DE |
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2022778 |
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Dec 1979 |
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GB |
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2099085 |
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Dec 1982 |
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GB |
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Primary Examiner: Leslie; Michael
Attorney, Agent or Firm: Davidson, Davidson & Kappel,
LLC
Parent Case Text
This is a continuation of prior International Application
PCT/DE2008/001438, filed Aug. 28, 2008, which claims priority to
German Patent Application DE 10 2007 045 034.8, filed Sep. 20,
2007, the entire disclosures of which are hereby incorporated by
reference herein.
The present invention relates to a hydraulic element, in
particular, for the arrangement in a pressure line between a master
cylinder and a slave cylinder of a hydraulic clutch operation
system, with housing that features a master-cylinder-side hydraulic
connection and a slave-cylinder-side hydraulic connection and
accommodates a valve arrangement.
Claims
What is claimed is:
1. A hydraulic element comprising: a housing having a
master-cylinder-side hydraulic connection and a slave-cylinder-side
hydraulic connection; accommodated in the housing, a valve
arrangement, the valve arrangement having a first valve body and a
second valve body, the first and second valve bodies being
supported in a floating manner inside the housing and displaceable
relative to one another against a force of a spring, wherein the
first valve body is an external valve and the second valve body is
an internal valve, the external valve body comprising a cup-shaped
valve cup supporting in a sliding manner a tube-shaped section of
the internal valve body, whereby the valve cup and the tube-shaped
section respectively have connection holes that can coincide with
one another depending on a relative position of the external and
internal valve bodies.
2. The hydraulic element as recited in claim 1 wherein the external
valve body comprises a valve head having an axial hole and a radial
hole connected with the axial hole.
3. The hydraulic element as recited in claim 1 wherein the external
valve body and the internal valve body each comprise a component
that prevents rotation of the external valve body and the internal
valve body relative to one another.
4. The hydraulic element as recited in claim 3 wherein the
component of the internal valve body is a finger and the component
of the external valve body is an axial groove, the finger being
guided in the axial groove.
5. The hydraulic element as recited in claim 1 wherein the internal
valve body comprises a valve head which forms a valve seat with the
housing in an axial end position of the valve body.
6. The hydraulic element as recited in claim 5 wherein the valve
head of the internal valve body leaves a gap relative to a
hollow-cylindrical section of the housing.
7. The hydraulic element as recited in claim 1 wherein the housing
comprises a clutch assembly on one side.
8. A hydraulic clutch operation system with a master cylinder, a
slave cylinder and a pressure line connecting the master cylinder
and the slave cylinder, wherein the hydraulic element as recited in
claim 1 is disposed in the pressure line.
9. The hydraulic element as recited in claim 1 wherein the
hydraulic element is for the arrangement in a pressure line between
a master cylinder and a slave cylinder of a hydraulic clutch
operation system.
Description
BACKGROUND
From DE 100 59 382, FIG. 6, in particular, a generic hydraulic
element, a so-called anti-vibration unit is disclosed, which
comprises two independent spring-loaded check valves. The opening
pressure in both flow directions can be determined individually by
spring preload for each direction. Such a part consists of many
components and is complicated in assemblage.
Hydraulic elements in which valve function is formed by means of
pinch valves for a flow direction.
Generic hydraulic elements known from the state of the art comprise
a variety of individual parts by which the assemblage is
complex.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a simple design
for such a hydraulic element, in particular, to be able to
manufacture this under the application of a few individual parts
for instance or individual parts with little accuracy
requirements.
The present invention provides a hydraulic element, in particular,
for the arrangement in a pressure line between a master cylinder
and a slave cylinder of a hydraulic clutch operation system, with
housing that features one master-cylinder-side hydraulic connection
as well as a slave-cylinder-side hydraulic connection and that
accommodates its valve arrangement wherein the valve arrangement
features two valve bodies that are supported inside the housing in
a floating manner, and that can be displaced relative to one
another against a spring force.
The valve arrangement comprises preferably an external valve body
and an internal valve body, whereby the external valve body
comprises a cup-shaped valve cup in which a tube-shaped section of
the internal valve body is supported in a displaceable manner,
wherein the valve cup and the tube-shaped section features at least
a connection hole that can be brought to overlap depending on the
position of the valve body relative to one another.
The outside valve body comprises preferably a valve head that
features an axial hole and a radial hole connected with the latter.
The valve head serves, in particular, the radial guide of the valve
body in a hollow cylindrical section of the housing.
The external valve body and the internal valve body comprise
preferably a means that prevents rotation in opposite directions of
both bodies. This means prevents both bodies from rotating in
opposite directions such that the holes cannot be brought to
overlap. The means comprises preferably a finger of the internal
valve body that is guided in an axial groove of the external valve
body. Alternatively, this function could be assumed, e.g., also by
the spring disposed between the two valve heads.
The internal valve body comprises preferably a valve head that
forms a valve seat with the housing in an axial end position of the
valve body. The valve seat seals the master-cylinder-side relative
to the section located between the two valve heads, so that fluid
can flow only via the axial hole in the internal valve body. With
this, the damping filter has different flow resistances in the two
flow directions.
The valve head of the internal valve body allows a gap preferably
relative to a hollow-cylindrical section of the housing. The valve
head fluid pushed out of the valve seat can flow through the
gap.
The housing comprises preferably a clutch assembly on one side. The
clutch assembly is mounted after the filter arrangement has been
mounted.
The present invention also provides a hydraulic clutch operation
system with a master cylinder, a slave cylinder and a pressure line
connecting this pressure line, whereby a hydraulic element
according to the invention is disposed in the pressure line.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following figures are exemplary embodiments of the invention
illustrated, based on the attached drawings, as follows:
FIG. 1 shows a schematic illustration of a hydraulic system for
operating a vehicle clutch.
FIG. 2 shows an exemplary embodiment of a damping filter according
to the invention in a longitudinal section.
FIG. 3 shows the damping filter according to FIG. 2 in Section
A-A.
DETAILED DESCRIPTION
FIG. 1 shows as an example of a hydraulic power transmission system
of a hydraulic clutch operation system 1 for a vehicle. The
hydraulic clutch operation system 1 comprises a master cylinder 2
in a common manner that is connected hydraulically via a hydraulic
pressure line 3 with a slave cylinder 4. The slave cylinder 4, for
instance, can be formed as annular slave cylinder, a concentric
slave cylinder, whereby an annular slave cylinder piston 5 is
supported in annular cylinder housing. The annular slave cylinder 4
and the annular slave cylinder piston 5 again enclose an annular
pressure chamber 16. Upon actuation of the slave cylinder piston 5,
via a release bearing 6, a disk spring 7 is activated in a common
manner. The disk spring 7 serves to activate a vehicle clutch 17.
The latter comprises a pressure plate 8, a counter pressure plate 9
and a clutch disk 10. The disk spring 7 is preloaded such that it
presses the pressure plate 8 onto a counter pressure plate 9 in the
preload direction, and in the process, it clamps a clutch disk 10
that is connected non-rotatably with a transmission input shaft,
between pressure plate 8 and counter pressure plate 9. The pressure
plate 8 and the counter pressure plate 9 are connected
non-rotatably with a crankshaft of an internal combustion engine.
When the slave cylinder 4 is pressurized, the disk spring 7 is
moved via the slave cylinder piston 5 and the release bearing 6
that decrease the pressure in its preload direction, the pressure
exerted by the pressure plate 8 towards the pressure plate 9, and
thus creating the frictional connection between the clutch disk 10
and pressure plate 8 or counter pressure plate 9, is released. The
master cylinder 2 comprises a master cylinder piston 11 that is
activated by means of a clutch pedal 12 via a pressure rod 13.
Housing of the master cylinder 2 and the master cylinder piston 11
disposed movably inside enclose a pressure chamber 15. A
pressure-less tank 14 is hydraulically connected with the pressure
chamber 15 in a pressure-less system, thus, the master cylinder
piston 11 is extended to the furthest position outside the master
cylinder 2.
For a hydraulic clutch operation system 1, as depicted in FIG. 1,
vibrations are transmitted to the slave cylinder 4 from the
combustion engine in particular from its crankshaft, via vehicle
clutch 17 components. These vibrations are generated inside the
pressure chamber of the slave cylinder 4 and thus inside the entire
hydraulic system, comprising the pressure line 3 and the master
cylinder 2--pressure vibrations noticeable on the clutch pedal, as
vibrations. To dampen these pressure vibrations (pressure
pulsation) a hydraulic element 18, hereinafter designated as a
damping filter 18, is disposed in the pressure line 3.
The hydraulic clutch operation system according to FIG. 1 is
familiar of course. Instead of using a concentric release bearing
as the slave cylinder 4, also other hydraulic release bearings can
be used, for instance, a lever release bearing that interacts with
a slave cylinder. Likewise, instead of an operation of the master
cylinder 2 with a clutch pedal 12, an electrical actuator or the
likes can be provided. Instead of exerting force on the disk spring
to open as done here, the clutch can also be closed by exerting
pressure (actively closed clutch). The embodiment of the master
cylinder as well as that of the slave cylinder and likewise that of
the clutch can be arbitrary; the prior depicted exemplary
embodiment is only one of many possibilities.
FIG. 2 shows a damping filter 18 according to the invention, in a
longitudinal section, FIG. 3 shows the damping filter of FIG. 2 in
Section A-A. The damping filter 18 essentially comprises
rotationally symmetrical housing 19 that on the one side comprises
hydraulic plug 20 for connecting the damping filter 18 with a
hydraulic socket of the pressure line 3 according to FIG. 1. The
plug 20 forms a slave-cylinder-side hydraulic connection. On the
side opposite the plug 20 of the housing 19, a socket assembly 21
is fitted as a clutch assembly with socket 30 for plug connection
in the housing 19. The socket 30 forms a master-cylinder-side
hydraulic connection. Obviously, plug 20 and socket 30 can be
swapped or both connections can be formed as plug or as socket. The
plug 20 and socket 30 of the socket assembly 21 can belong to the
same hydraulic plug-socket connection; in this case, one could
connect the plug 20 of a damping filter 18 with the socket 30 of
another damping filter 18, but they also belong to different types
of hydraulic plug-socket connections.
The housing 19 comprises a hollow-cylindrical section 22 that on
one side transforms into a cup-shaped bottom section 23 of the plug
20, and on the other side, it transforms via a conical section 25
in a second hollow-cylindrical section 24 for accommodating the
socket assembly 21. The plug 20 features a through hole 26 that
extends up to the hollow-cylindrical section 22.
The plug 20 comprises a seal ring 27 as well as a ring groove 28.
Between the seal 27 and the ring groove 28 is a conical section 29
disposed, so that also the diameter of the plug 20 increases in
this section. The socket group 21 features the receiving socket 30
that is formed such that it can accommodate a plug similar to that
formed by plug 20. Thus, a formed wire spring 31 engages with a
corresponding ring groove 28 of the plug to be accommodated, which
is introduced into the accommodating opening 30. The socket group
21 carries in a ring groove 32 a seal ring 33 that seals the gap
between the housing 19 and the socket group 21. The socket group
21, for instance, can be screwed together with the housing 19,
likewise, also a bayonet lock or a similar means can be provided or
both parts can be glued or welded with one another or, for example,
it can be friction-welded. A conical section 34 of the socket group
21 and a corresponding conical section 35 that adjoins to the
second hollow-cylindrical section 24, serve for axial positioning
of the socket group 21 relative to the housing 19.
Between the socket group 21 and the bottom 23 a valve arrangement
36 supported. The valve arrangement 36 comprises an external valve
body 37 and an internal valve body 38 that are supported in the
housing 19 in a floating manner. The external valve body 37
comprises essentially of a cup-shaped valve cup 39 that features a
blind hole 40 with an internal diameter d2. The valve cup 39
transforms to its cup bottom side into a valve head 41. The valve
cup 39 has an external diameter D2 that is obviously greater than
the internal diameter d2. The valve head 41 has an external
diameter D3 that forms a clearance fit with the internal diameter
of the hollow-cylindrical section 22. The valve head 41 features an
axial hole 42 that connects the through-hole 26, via a radial hole
43, with the hollow-cylindrical section 22. The internal valve body
38 comprises a tube-shaped section 44 with an external diameter
that with the internal diameter d2 of the valve cup 39 a clearance
fit. The tube-shaped section 44 is enclosed by the valve cup 39 and
is supported in a sliding manner in this axial direction. The
internal valve body 38 comprises furthermore a finger 45 that
essentially extends in essentially parallel to the tube-shaped
section 44 and meshes with an axial groove 46 that is provided in
axial direction inside the valve cup 39. The finger 45 together
with the axial groove 46 provides non-rotational locking of the
internal valve body 38 relative to the external valve body 37. The
internal valve body 38 comprises an axial hole 50 that extends in
axial direction as well as a valve head 47 that is essentially
conical in shape. The valve cup 39 of the external valve body 37
features a connection-hole 48, the tube-shaped section 44 of the
internal valve body 38 features a connection-hole 49. The
connection hole 48 transforms into a longitudinal groove 54. When
the connection holes 48 and 49 coincide at least partially, then
the axial hole 42 is hydraulically connected with the axial hole
50, so that fluid can flow through the damping filter 18. Between
the valve head 41 of the external valve body 37 and the valve head
47 of the internal valve body 38 is a spring 51 disposed that
presses the two valve bodies 41, 47 and hence the internal valve
body 38 and the external valve body 37 apart.
If fluid is pushed from the master cylinder side towards the slave
cylinder, then on the circular surface of the valve head 47
designated with the double arrows A1 of the internal valve body 38
a pressure that depends on the level of the pressure difference and
on the size of the surface A1 exerts a force in the direction of
the arrow 52 on the internal valve body 38. In this way, the
internal valve body 38 is pressed against the force of the spring
51 in the direction of the arrow 52. Depending on the level of the
force resulting from the pressure difference, this movement occurs
against the force of the spring 51 so far until the connection
holes 48 and 49 coincide. Now fluid can flow from axial-hole 50 via
the connection holes 48 and 49, the remaining section of the
hollow-cylindrical area 22, the radial hole 43 and the axial hole
42 in the through-hole 26. Between the external circumference of
the valve head 47 of the internal valve body 38 and of the wall of
the hollow-cylindrical section 22 a gap remains, through which
fluid can flow as well. In the pressure-less state, as depicted in
FIG. 2, the valve head 47 with the socket group 21 forms a valve
seat 53 that practically does not allow fluid to flow-through.
When engaging the clutch while the pressure on the
slave-cylinder-side is higher than that on the master cylinder
side, a resultant surface area A2 is effective; this is the surface
determined by the internal diameter d2 of the valve cup 39 and a
pressure force depending on the area A2 and on the pressure
difference between master-cylinder-side and slave-cylinder-side in
the direction opposite to the arrow 52. The hydraulically effective
surface area when the pressure on the slave-cylinder-side is higher
than on the master-cylinder-side corresponds to the cross-section
area of the blind hole 40, since all other pressures forces on the
external valve body cancel out, ultimately the pressure of the
slave cylinder side acts via the hole 43 also in the section in
which the spring 51 is disposed. If this pressure force exceeds the
force of the spring 51, then the external valve body 37 will be
moved against the arrow 52 direction, so that the connection holes
48 and 49 coincide or at least partially coincide and release the
flow--depending on the pressure difference of master-cylinder-side
and slave-cylinder-side, and on the spring-51 force. The connection
holes 48 and 49 can also be brought to coincide in both flow
directions depending on the positions of the valve bodies relative
to one another.
The internal leakage between the master-cylinder-side and
slave-cylinder-side is determined by the gap featured by the guide
of the internal valve body 38 in the external valve body 37. During
vacuum pressure charge, the slave cylinder is evacuated via this
gap.
REFERENCE SYMBOLS LIST
1 hydraulic clutch actuation 2 master cylinder 3 pressure line 4
slave cylinder 5 slave cylinder piston 6 release bearing 7 disc
spring 8 pressure plate 9 counter-pressure plate 10 clutch disk 11
master cylinder piston 12 clutch pedals 13 push rod 14
pressure-less tank 15 pressure chamber 16 pressure chamber 17
vehicle clutch 18 damping filter 19 housing 20 plug 21 socket
assembly 22 hollow cylindrical section 23 bottom section 24 second
cylindrical section 25 conical section 26 through hole 27 seal ring
28 ring groove 29 conical section 30 mounting socket 31 formed wire
spring 32 ring groove 33 seal 34 conical section 35 conical section
36 valve arrangement 37 external valve body 38 internal valve body
39 valve cup 40 blind hole 41 valve head 42 axial hole 43 radial
hole 44 tube-shaped section 45 finger 46 axial groove 47 valve head
48 connection hole 49 connection hole 50 axial hole 51 spring 52
arrow 53 valve seat 54 longitudinal groove
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